Ok your Question is older than one year but i hope it is not to late if i answer it now.
First of all LHCityLine doesn't take any applications by now. Their current schedule and fleet can be operated with the new hired but they are planning to start hiring from spring 03 again.
As far as i know the training contract with the RWL flight academy had been cancelled because CLH has enough applicants from the free market that fullfill their standart. But there is a new flight academy called Intercockpit
www.intercockpit.com they are planning to continue the CLH programm in the near future but actually they are waiting for some decisions which could result in massive changes within CLH and Team Lufthansa. So they are not any farer than in a thinking and planning process.
Anyhow the selection process for CLh ab intio rogramm consists of 2 parts. First is the "BU" 2 days full of english math and physic tests combined with a lot of reaction tests.
www.hh.dlr.de there you'll fnd what you can expect of the BU.
If you succeed this part you will be invited to the also 2 day long "FQ." First day is has 2 group games, you have to work on a certain problem, everybody should be nice to everybody and work together as a group but never forgetting what the own targets for that game are. Next you have one or two difficult talks. A situation with a colleague or an unruly passenger where you have show your social competence.
second day is a simulator test and a interview. A selection will be made after the first day after the sim ride and of course after the interview. The upper HP should provide you with all infos you need.
regards Bjoern